Definate thumbs up.
The bike is very stable as long as you engage the bolt that takes the slack out of the receiver. If not, it just wags around a bit, no big deal.
The unit does positively lock in the up position with a through-bolt.
It won't scratch your frame at all, period, there are 1/4" rubber mats on the surface spars.
The only problem I've had with mine is a bad jack seal which is easily fixable and only slightly annoying.
The units are pretty beefy, I don't think you can go wrong.